Conventional mode-coupled ultrasonic motors operate based on coupled modes

and frequency simple merging is needed to eliminate the resonant frequency deviation between modes

but there are difficulties in simple merging and unsatisfactory results. In this paper

the characteristics of the circular symmetric structure are used to determine the operating modes of the stator

which simplifies the design process of the ultrasonic motor and significantly reduces the difficulty of frequency merging and the residual resonance frequency deviation through the symmetric design of the structure. A double-arc epicycloid drive trajectory is proposed for this ultrasonic motor. Under excitation signals with a peak-to-peak input voltage of 200 V

it achieves a driving speed of 727.98 mm/s

1.8 times faster than the conventional elliptical trajectory. To enhance the output performance of the ring-shaped ultrasonic motor

this study optimizes the initial structure by using response surface methodology

with driving speed and force as the objectives. A new experimental prototype is fabricated based on the optimized parameters

achieving a speed of up to 990.05 mm/s under the same conditions

which represents an improvement of approximately 1.36 times compared to the original prototype. The maximum driving force reaches 3.48 N

an increase of 1.12 N compared to the original prototype.